This application relates to a propeller pitch change mechanism wherein torque compensation is provided from a drive input.
Propeller pitch change mechanisms are known, and are utilized in a propeller assembly which carries a plurality of blades. The assembly is driven to rotate, and carries the blades for rotation. However, the pitch angle of the blades can be adjusted to provide an adjustable thrust from the rotation of the assembly.
A pitch change mechanism typically has included a gear train which causes the blade to rotate within a hub that carries the blade. There are challenges in the prior art in that there are forces on the blades which tend to force the blades toward a flat position wherein the provided thrust is minimized.
There is a total twisting moment (“TTM”) on each blade which is the algebraic sum of a centrifugal twisting moment, an aerodynamic twisting moment, and friction which always resists the direction of motion.
The prior art systems have been required to overcome all of these forces. This TTM is large, and causes parasitic loss of energy when the pitch change mechanism must drive the blade, and overcome the forces.